Surly tire TPI

This was discussed a bit here:

http://forums.mtbr.com/showthread.php?t=668029

Something I found:

http://www.cyclingnews.com/features/...f-wheel-energy

"Higher thread counts aren't always better:
According to Wheel Energy, higher thread count casings are generally lighter and suppler than tyres with lower thread counts since they absorb less rubber during the vulcanisation process (non-vulcanised tyres such as most high-end tubulars exhibit their own characteristics).

However, they also suffer from decreased puncture resistance since the individual cords are thinner and easier to cut. Interestingly, Wheel Energy claims medium-count casings (around 60tpi) may offer the best all-around performance for everyday use. As compared to 120tpi casings, they can actually roll faster and are much more resistant to cuts while often carrying just a slight weight penalty.

If cut resistance is highest of your list of priorities, 30tpi tyres are apparently the way to go but you can also expect them to be heavy and slow rolling."

I note that this is about skinny little road tires, but cheap and durable are what I'm planning on next.